Hi,
when you right-click on the tray icon --> Tools, the menu that appears has item both for MySQL and MariaDB. MySQL is on port 3306, MariaDB is on port 3307.
However, the "Test for port xxxx" ("Tester le port..." in the French version that I use) is for 3306 in both cases. It should be 3307 for MariaDB.
There is alos a mariaDB, that should be MariaDB for consistancy reasons.
(tested with Wamp 3.1.9, I've not checked in 3.2.0 if fixed)